1. Technical Field
The present disclosure relates to an LED lighting apparatus, and more particularly, to an LED lighting apparatus with an improved heat radiation property, which is capable of effectively radiating heat generated therein.
2. Related Art
In order to reduce energy, a lighting apparatus is designed to use a light source having high light emission efficiency based on a small amount of energy. Recently, an LED has been used as a representative light source of the lighting apparatus. The LED is differentiated from other light sources in terms of various aspects such as energy consumption, lifetime, and light quality.
Since the LED is driven by a current, a lighting apparatus using the LED as a light source requires a large number of additional circuits for current driving.
In order to solve the above-described problem, an AC direct-type lighting apparatus has been developed to provide an AC voltage to the LED.
The AC direct-type lighting apparatus is configured to convert an AC voltage into a rectified voltage, and control the LED to emit light through a current driving operation using the rectified voltage. Since the AC direct-type LED lighting apparatus uses a rectified voltage without using an inductor and capacitor, the AC direct-type LED lighting apparatus has a satisfactory power factor. The rectified voltage indicates a voltage obtained by full-wave rectifying an AC voltage.
The lighting apparatus may include a light source unit, a power supply unit, and a driving unit. The light source unit may include a plurality of LED groups, the power supply unit may provide a rectified voltage using an AC voltage, and the driving unit may drive the light source unit.
Among the units of the lighting apparatus, the LED groups of the light source unit generate heat at a considerably high temperature, when emitting light, and the driving unit also generates heat at a high temperature due to a driving current corresponding to the light emission.
When the heat of the LED groups or the driving unit is not effectively discharged, a line pattern may float due to a difference in thermal expansion coefficient between the line pattern and a printed circuit board (PCB) or the lifetime of the LEDs included in the LED groups may be reduced by accumulated thermal fatigue.
The driving unit is arranged on the PCB without considering the influence of heat radiated from the LED groups. Thus, the driving unit may be positioned in the environment which is not suitable for heat radiation. When the heat radiation is not smoothly performed due to such an environment, the driving performance and reliability of the driving unit may be reduced.
For such reasons, the light emission property and brightness of the LEDs may be degraded, and the entire driving performance and reliability of the lighting apparatus may be degraded.
Thus, the lighting apparatus needs to be designed to have an improved heat radiation property.